Itinerant magnetism of chromium under pressure: a DFT+DMFT study.

We consider electronic and magnetic properties of chromium, a well-known itinerant antiferromagnet, by a combination of density functional theory (DFT) and dynamical mean-field theory (DMFT). We find that electronic correlation effects in chromium, in contrast to its neighbours in the periodic table, are weak, leading to the quasiparticle mass enhancement factor ${m^*/m \approx 1.2}$; our results for local spin-spin correlation functions indicate that the local magnetic moments are not formed. The non-uniform magnetic susceptibility as a function of momentum possesses sharp maxima, corresponding to Kohn anomalies, close to the wave vector ${{\mathbf Q}_{\rm H}=(0,0,2\pi/a)}$ ($a$ is the lattice constant), similarly to previous results of DFT at ambient pressure. We find that these maxima are preserved by the interaction and are not destroyed by pressure. Our calculations qualitatively capture a decrease of the N\'eel temperature with pressure and a breakdown of itinerant antiferomagnetism at pressure of $\sim$9 GPa in agreement with experimental data, although the N\'eel temperature is significantly overestimated because of the mean-field nature of DMFT.